The city's ambitious plan to keep sewage out of drinking water relies on trees, not tunnels

Christine Knapp and her neighbors in South Philadelphia are used to seeing dirty water flood their basements and back up their plumbing during heavy downpours. A live rat once scrambled out of a toilet bowl in a nearby house, Knapp said, and some of her friends joke that they can see the color of their neighbors' toilet paper whenever it rains.

Although Philadelphians live in a city with one of the nation's oldest sewer systems -- including more than 3,000 miles of aging subterranean pipes -- their stormwater management problems are shared by hundreds of communities across the country. Nearly 800 U.S. cities rely on systems that collect sewage and stormwater runoff in the same pipes. They're designed to overflow when it rains, meaning that even minor storms can result in a flood of human waste pouring into local rivers and streams.

That adds up to roughly 850 billion gallons of untreated water polluting the nation's waterways each year, according to the U.S. Environmental Protection Agency. The result is contaminated drinking water, closed beaches, polluted shellfish beds, and many more environmental and health concerns. Studies of sewage overflows cited in a recent New York Times series have shown increased cases of serious diarrhea among children in Milwaukee after rain storms and estimated that as many as four million people in California become sick every year from swimming in water polluted by untreated sewage.

"This isn't just about our basements," says Knapp, who crusades for clean water with Citizens for Pennsylvania's Future. "It's about the water that comes out of our taps at the end of the day."

The EPA wants cities to fix their overflow problems to comply with federal Clean Water Act standards. The traditional way to handle stormwater is to steer it as quickly as possible down sewers and into waterways, building expensive underground tunnels and tanks to handle the overflows. In Philadelphia, estimates for the cost of that project run to $7.5 billion, in part because the city would have to tunnel under its existing waterways and aging pipes to build the new tunnels and cisterns.

So instead, the city has embraced a very new idea: Don't collect the stormwater at all. Instead, let it fall on an environmentalist's paradise of 300,000 newly planted trees, urban farms and rain gardens, new wetlands, rain barrels, green roofs, and porous pavement.

All of that "green infrastructure," as it's called, will serve as a sponge to soak up a significant portion of the 13 billion gallons of combined sewer runoff that the city's four watersheds absorb annually. Experts say it's the most ambitious and environmentally friendly stormwater management plan in the country and could serve as a model for cities nationwide.

"Philadelphia is way ahead of everyone else on this," says Ken Kirk, executive director of the National Association of Clean Water Agencies.

Philly's green scheme will benefit the city in ways far beyond stormwater control, officials promise. The plan will create thousands of jobs building and maintaining the green infrastructure, improve air quality, boost property values, reduce energy use, expand opportunities for water recreation and replace vacant and abandoned lots with parks and other open space, supporters say.

"For the past 150 years, we have been putting down concrete barriers to nature and ‘protecting' our population from the environment," says Howard Neukrug, director of the Philadelphia Water Department's Office of Watersheds. "This plan is about partnering with the environment to create a better quality of life."

Philadelphia officials outlined the $1.6 billion, 20-year plan in a 3,369-page report called "Green City Clean Waters" submitted to the EPA in September. The EPA didn't approve it immediately, but returned it to the city in December with requests for changes. Jon Capacasa, director of water protection for the EPA's Region 3 (which covers the MidAtlantic states), said he expects the revised plan to be ready for EPA approval by late spring.

"This is clearly groundbreaking," Capacasa says, "because it's the largest-scale commitment to use these techniques by a larger city and to use them for regulatory compliance, as well as for community quality-of-life issues."

Other cities, including Los Angeles, Pittsburgh, and Milwaukee, are also adopting green infrastructure plans, often writing them directly into building and development codes, said David Beckman, co-director of the Natural Resources Defense Council's water program and an advocate for what's called "low-impact development." He cited Chicago, where the city has built more than 2 million square feet of green roofs and passed a stormwater ordinance requiring new developers to capture rainwater and reduce impermeable surfaces.

Neukrug said Philadelphia has little choice but to go green. The city has cut library, fire-protection, recreational, and other services in recent years, and a quarter of residents live in poverty. So the cost savings of the green infrastructure plan made it the clear choice, although funding remains uncertain. More than $335 million already is committed, and Neukrug expects a blend of public and private support to foot the rest of the bill.

City officials also aim to persuade residents to conserve water so that less is lost down the drain. Still, customers will likely see rate increases. And in February, the city's water department will adopt a stormwater "tax." Instead of charging businesses and other nonresidential customers for the water they use, the department will base bills on how much impervious surface a property has.

That means properties that generate more water runoff, such as parking lots, will be held responsible for their role in the city's stormwater problem.

Still, because urban greening is a new technique, skeptics worry that environmental strategies to slow overflows are unproven -- and therefore might not produce the results that supporters expect.

Others worry that bureaucracy will stymie success. To work, the plan requires countless city agencies, community groups, and citizens to cooperate. It also requires changes in zoning and building codes.

"It's a lot easier to manage building a big tunnel and throw all your resources at a single project than to persuade people to rethink how they've always done things," says Robert Traver, a civil and environmental engineering professor at Villanova University and director of the Villanova Urban Stormwater Partnership. "It really changes the paradigm for how we've been operating.".

Traver was part of a team led by NRDC that favorably reviewed the Philadelphia plan. "It really is easier to work with nature than to try and fight it."

The plan's biggest hitch is that it falls slightly short of the EPA's edict that the city must capture 85 percent of its overflows in order to fully comply with the Clean Water Act. The city says green infrastructure would catch 80 percent of overflows.

Whether or not the proposal gets approved, Philadelphia officials aren't waiting for the feds' final OK. They've already partnered with schools, community groups, and recreation officials to create rain gardens and other stormwater-absorbing strategies. And they've piggybacked their green goals onto the routine work of city laborers, so that when a potholed street needs to be repaved, for example, the workers replace it with porous pavement that will let stormwater percolate through.

The city's old age -- and persistent need for repair -- translates into plenty of opportunities to implement the green strategies.

"As urban environmental issues go, stormwater management is as big as they come," Neukrug says. "The kind of response that we're getting from the environmental community and other cities says to me that we're on to something. This is something that is really attractive to all sides."

Dana DiFilippo is a veteran newspaper and magazine reporter. She currently works at the Philadelphia Daily News and has written for the Cincinnati Enquirer, the Bucks County Courier Times, the North Hills (Pa.) News Record, American Baby magazine, an... READ MORE >

Oh my gosh! I am so disturbed by all of this. Bureaucrats take so long to push anything through, so any resolution will likely be years away...and people have to open their toilet lids to be greeted by RATS??? Please follow the developments and post online-- as a resident, I'm concerned.

By putting forth such an ambitious plan, the city forgot about what this will do to small business within the city. This plan has raised water bills for small busineess 400%+ in most cases. and will continue increasing for the next 3 years. This will force businesses to cover such an increase. How will they do it...How do they pay for a 50,000.00 year water bill? Lay off employees, dont expand, don't hire new employees, Leave the City, Close their doors---thats how. What new business would want to come into the city with these kinds of bills for water??? None I know of.
The City of Philadelphia needs to re-visit the plan and try to make it more feesable for the small business to survive in this economy. Extend the plan, revamp it...Dont put forth such an ambitious plan, Instead of doing 85% do 50%, do 40% and increase it every year...why jump in while we are still hurting economically.

OnEarth is published by the Natural Resources Defense Council. The opinions expressed by its editors and writers are their own and do not necessarily reflect the policies or positions of NRDC. Learn more.